UI failed to load on latest version

new version issue cannot access program due to UI failure. Re-installed twice with same result.

Perform a repair of avast.
If that doesn’t solve it perform a real clean installation of the latest avast version.

repair worked - thank you for quick reply and solution.

spoke to early only worked once and now back to same issue, after running performance programs.

What Windows version are you using ?
I know there is such problem with Vista, that Avast is aware off.

Greetz, Red.

i am using windows 10 x64, old version worked great; just removed it completely and re-installed it, hopefully will be ok

I have the same problem with my win 10 64bit
Once I disabled the behavior shield, then it works properly.

seems to be stable now after complete uninstall and re-install with new version.

I have windows vista, I have the same problem, Avast can’t run ('UI failed etc.) so I cleaned up Avast and reinstall same version (Avast 17.1.2286 (build 17.1.3394.0) as you said.
Avast now runs but I have no GUI when doing open the user interface (white popup). Does anybody find the solution? Now I access to my settings via the option “about Avast” :-\

Haven’t encountering this issue, yet. But…
Does Windows visual effects (particularly Aero in Vista and 7) cause this problem?
Or an avast service is abruptly stopped?

If reinstallation doesn’t fix it, it shouldn’t be a corruption problem.

Problem persists with UI, installed Beta version which worked after install initially but then returned with the same issue. Not sure where to go from here. Never experienced this with old versions.

Follow instructions: https://www.avast.com/faq.php?article=AVKB33#artTitle

after installing an upgrade UI is working again.

After UI failed to load, my PC does not work anymore. Now I have a black screen after login on windows (Vista). Only cursor of mouse can move (CTRL ALT DEL does not work), I have to do a hardware reset. Only access on windows by mode without failure (F8) works >:(

Update to the latest version (17.2.2288): https://forum.avast.com/index.php?topic=197955.0